<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>iframe</title>
    <style>
        body{
            margin: 0;
        }
        .header{
            height: 80px;
        }

        .header iframe{
            height: 100px;
        }
        .footer{
            height: 100px;
        }
        .body{
            height: 800px;
        }
    </style>
</head>
<body>
    <div class="header">
        <iframe src="frame/header.html" frameborder="0" width="100%"></iframe>
    </div>
    <div class="body">
        <iframe src="frame/body.html" frameborder="0" width="100%" height="800px"></iframe>
    </div>
    <div class="footer">
        <iframe src="frame/footer.html" frameborder="0" width="100%" height="100px"></iframe>
    </div>
</body>
</html>